A multi-scale flood vulnerability assessment of agricultural production in the context of environmental change: The case of the Sangkae River watershed, Battambang province

Flooding on Cambodian land use systems is not a new phenomenon but its significance
has increased in the context of global environmental changes. This study aims to assess
the vulnerability of agricultural production to floods in the Sangkae River watershed
in Battambang province, Northwestern Cambodia. The study was conducted in
conjunction with the provincial spatial planning team hosted by the Provincial
Department of Land Management and can be viewed as a first step toward a flood
management decision-making tool for provincial authorities.
The assessments rest on specific dimensions of vulnerability (exposure, sensitivity and
adaptive capacity) at different levels in a multi-scale framework: spatial scale
(watershed, commune and household); temporal scale (decade, year and season);
and institutional scale (national policy, provincial operating rules and communal
agencies). The analysis rests on triangulation of qualitative and quantitative data
(time-series rainfall data, land use systems, participatory flood mapping, commune
workshops (n=31), social-economic statistical databases, in-depth interviews with
relevant institutions (n=5) and household surveys (n=162).
Intensification of rainfall since the 1920s has increased the risk of flooding in the
Sangkae River watershed during the late rainy season, particularly in the upstream
area. Using an indicator-based approach, we discovered that the vulnerability of
communes is highly dependent on the agro-ecology of land use systems. The household
assessment reveals the variability of adaptive capacity between households according
to their food security status and income portfolio. Agricultural innovation and structural
adaptation to flood are scarce; the households mostly cope with flood through credit,
external aid and de-capitalization (sale of household assets). These coping mechanisms
adopted by farmers do not reduce vulnerability but reinforce it.The application of this assessment methodology provides nested pictures of vulnerability
at different levels and scales and we argue that a dialogue between these levels
and scales is necessary to understand the nature of the vulnerability and to act to
reduce it. Using these different typologies of vulnerability, this approach enables
recommendations to be formulated to reduce vulnerability through better horizontal
and vertical integration of institutions and agencies, and effective collective action.